Electromagnetic actuated switch lever detent



Oct. 17, 1950 J, c, w sd 2,525,846

ELECTRDMAGNET ACTUATED SWITCH LEVER DETENT Filed Sept. 27, 1946 4 0 37 4I a Z 3A/5 INVENTOR Patented Oct. 17, 1950 I ELECTROMAGNETIC ACTUATEDSWITCH LEVER DETENT Jack C.'Wilson, Garden City, N. Y., assignor to TheSperry Corporation, a corporation of Delaware Application September 27,1946, Serial No. 699,677

' 7 Claims.

This invention relates to a switch for electric circuits and moreparticularly to an electromagnetic switch and has for its object'theprovision of a simple switch structure having manually operable contactstogether with a mechanism controlled by an electromagnet for moving andlocking the switch in a predetermined position. i

The switch disclosed herein is' particularly useful as a control elementin interlock circuits such as are used in connection with automaticpilots for airplanes. I

Other features and objects of the invention will be found in thefollowing description, given with the aid of the accompanying drawings,of which Figs. 1 and 2 are side views in elevation showing respectivelythe switch in off and in on positions; I

Fig. 3 is a plan view of the switch, and

Fig. 4 is a plan view of the switch bracket.

Referring particularly to Fig. 4, the switch comprises an approximatelyU-shaped bracket having spacedarms'll and I2 connected by a yoke it eacharm being formed with a mounting plate is at the end thereof. A switchlever 55 having an operating knob IE attached at one end is disposedbetween arms I! and I2 of the bracket on a pivot I8 supported by botharms.

A roller 2 mounted on the opposite end of the switch levercooperateswith a dOg'Zl formed with a curved surface 22'disposed towardthe roller, the dog being mountedbetween arms II and I2 of the bracket,on a pivot 23 supported thereby which extends substantially through themidpoint of the dog'. The dog which is controlled by an electromagnet,to be described, is used to lock the switch in one of its two positions,which for the purpose of the present description will be assumed to Manopen, or off position. The dogis also used in operating the switchautomatically from on to off position.

Below pivot 23 and spaced therefrom, the dog carries a pivot 25which'projects from opposite sides thereof into openings in flaps 26extending upward on opposite sides of the dog from a link 2'! which islooselyattached to an armature 28 of an electromagnet 29. Link 21 isformed with a relatively narrow strip 30 or extension at the end thereofwhich extends through an opening in the upper part of armature 28 wherethe strip is bent at an angle to engage the armature.

The magnet and armature are attached to lever is attached by screws 36shown by dotted lines to plates M of bracket [0. Plate 35 extends belowplates l4, and the magnet 29 and an L-shaped bracket 31 are attached tothis lower portion of the plate by a screw 38. The armature is attachedtoa normally fiat spring 39, which serves as a support as well as aretractile spring therefor, .19 spring being slightly bent. as shown inFig. 2 when the magnet is energized. One end of spring 39 is secured byany suitable clamping arrangement to bracket 40, which preferably allowssome adjustment of the spring for regulating the position of thearmature, whlle the opposite end of the spring may be secured in anysuitable manner to the armature such as by eyelets or by a clamp 4|.

Referring to Fig. 3, a spring 45 is attached at one end to a plate 46secured by screws 41 to the upper surface of yoke l3 of the bracket Ill.The opposite end of spring 45 is attached to a pin 48 fixed to lever IS,the spring tending to move the switch lever to the position shown inFig. 1.

A nest of contacts generally indicated by the reference character 49 isattached by screws 50 to the underside of plate 46. The contacts of thenest are operated, as shown in Figs. 1 and 2 by a pin 5| attached tolever l5 whichengages an insulating strip 52 attached to the uppermostof the contacts when the switch is positioned as shown in Fig. 2. In theopposite position of the switch, pin 5| is clear of the insulating strip52. While a contact nest of but three spring contacts is shown, aconsiderably greater number of contacts could be used if required. Theend portion of plate 46 which supports the contacts is offset to oneside of the magnet providing ample space for supporting additionalcontact springs.

A notch is formed in the side of dog 2| opposite the curved surface 22thereof and the lower surface 55 of the notch engages the under side ofthe endportion' 43 of the bracket I0 and serves as a stop for thearmature, as shown in Fig. 1 when the magnet is deenergized.

The switch operates as follows: When the magnet 29 is deenergized,spring 39 on which thearmature 28 is mounted straightens out and swingsthe armature away from the polepiece of the magnet, and link 21 turnsdog 22 on its pivot 23 in a clockwise direction until the lower surface55 of the notch in the dog engages the underside of yoke l3 of bracketl0 arresting further movement of the assembly. The upper end of the dogis then positioned under the arm of the switch lever I5. carrying roller28 thereby blocking the lever against movement in a counterclockwisedirection and pin is disengaged from the contacts of the contact nest.

When magnet 29 is energized, the armature 28 turns the dog in acounterclockwise direction moving the upper end thereof clear of thepath of roller 20. With the magnet thus energized lever [5 may beoperated at will in either direction to effect corresponding operationof the contacts of the contact nest.

On rotating switch lever [5 in a counterclockwise direction from theposition shown in Fig. 1 to that shown in Fig. 2, which is possible onlywhen the magnet is energized, spring 45 is stretched and roller 20 onthe lever arm engages the curved surface 22 of the dog at some pointbelow pivot 23. Continued movement of the lever causes the roller 20 tocam the dog slightly in a clockwise direction about its pivot 23 andagainst the force exerted on the dog by the mag net until the rollerpasses below the dog when the lower end thereof snaps in front of theroller due to the continued force exerted on the dog by the magnetthereby releasably retaining the lever in the position shown in Fig. 2against the tension of spring 45 which constantly tends to move thelever to the position shown in Fig. 1. If magnet 29 becomes deenergizedwhen the switch lever is thus positioned, spring 45 will becomeeffective instantly to displace the lever to its opposite position shownin Fig. 1. Assuming, however, that magnet 29 remains constantlyenergized for the time and the switch lever has been moved to theposition shown in Fig. 2, then manual pressure on the switch lever in aclockwise direction will cause roller 20 to bear against the slantingedge of dog 2| rocking the dog slightly in a clockwise direction on itspivot against the force of the magnet until the roller passes beyond thelower retaining edge of the dog when the lever is free to complete itstravel to the position shown in Fig. 1 under the influence of spring 45.

A lever actuating spring 45 may be selected which will apply appreciableforce to the switch lever when the magnet 29 is deenergized, and thisforce can be utilized in certain applications to operate or coordinateother external apparatus with the movements of the switch. Lever I5 isformed with an arm 56 to which is pivoted in oilset relation a link 51.Actuation of the switch lever effects corresponding reciprocation of thelink. In a specific application of the switch, a link similar to link 51but provided with a forked end portion is being used to centralize acontrol potentiometer for an automatic pilot when the switch isreleased.

Since many changes could be made in the above construction and manyapparently widely different embodiments of this invention could be madewithout departure from the scope thereof, it is intended that all mattercontained in the above description or shown in the accompanying drawingsshall be interpreted as illustrative and not in a limiting sense.

What is claimed is:

'1. A switch comprising a bracket, a movable contact operating leverpivotally mounted on the bracket movable to either of two positions, adog comprising an elongated member pivotally mounted at substantiallyits midsection on the bracket beyond the end of the lever, anelectromagnet having an armature pivotally coupled with the dog near oneend thereof eifective to rock the dog on its mounting to position eitherof opposite end portions of the dog in the path of the lever to engagethe lever and restrain the movement thereof in either of two directions,one end portion of the dog being formed to lock the lever againstmovement when engaged thereby, the opposite end of the dog being formedwith a cam surface effective to engage the lever and yieldingly restrainthe same against movement.

2. A switch comprising a bracket, a movable contact operating leverpivotally mounted on the bracket movable to either of two positions, adog comprising an elongated member pivotally mounted at its midsectionto the bracket beyond the end of the lever, an electromagnet having aspring biased armature pivotally coupled to the dog near one end thereofeffective to rock the dog on its mounting according to the energizationof the electromagnet to position either of opposite end portions of thedog in the path of the lever, one end portion being effective when inthe path of the lever to lock the lever against movement when in apredetermined position, spring means connecting the lever and anextension of the bracket to bias the lever toward said position, theopposite end portion of the dog being formed with a slanting surfacewhich when positioned in the path of the lever is effective toyieldingly restrain movement thereof by the spring means.

3. A switch comprising a bracket, a contact operating lever movable toeither of two positions of rest, pivotally mounted in the bracket, aspring connecting an extension of the bracket with the lever efiectivetomove the lever to a first of the positions of rest, a dog forretaining the lever in either of the positions of rest, comprising a barpivotally mounted at substantially its midsection on the bracketimmediately beyond an end of the lever, an electromagnet having a springbiased armature coupled to the dog near one end thereof effective inaccordance with the operation of the armature to position either ofopposite end portions of the dog in the path of the lever, the dog beingso formed as to block movement of the lever when in said first positionof rest on a predetermined operation of the armature, and on an oppositeoperation of the armature, to yieldingly hold the lever againstactuation by the first mentioned spring when the lever is in a second ofits positions of rest.

4. A switch comprising a bracket, a contact operating lever movable toeither of two positions of rest pivotally mounted in the bracket, aspring connecting an extension of the bracket with the lever effectiveto move the lever to a first of the positions of rest, a dog forretaining the lever in a second of the positions of rest comprising abar pivotally mounted at substantially its midsection on the bracketbeyond the end of the lever, an electromagnet having a spring biasedarmature pivotally connected to the dog efiective on energization of theelectromagnet to rock one end of the dog into the path of the lever toyieldingly hold the end of the lever against the force exerted thereonby the first mentioned spring, a cam surface formed on said end of thedog where engaged by the lever permitting the dog to be cammed out ofthe path of the lever momentarily on manual operation of the leverwhereby the lever may be freely operated to either of its positions ofrest while the electromagnet is energized.

5. A switch comprising a bracket, a contact operating lever movable toeither of two positions of rest pivotally mounted in the bracket, springmeans connecting an extension of the bracket with the lever effective tobias the lever toward a first of the positions of rest, a dog forretaining the lever in a second position of rest comprising a barpivotally mounted at substantially its midpoint on the bracket beyondthe end of the lever, an electromagnet, an armature therefor having aretracting spring, a link coupling the armature to the dog whereby thearmature is efiective on energization of the electromagnet to rock oneend of the dog into the path of the lever to yieldingly engage and holdthe lever against the force exerted by the spring means, a slantingsurface formed on said end of the dog where engaged by the levereffective when manual force is applied to the lever to earn the dogmomentarily out of the path thereof whereby the lever may be operatedfrom one position to another when the magnet is energized, the armaturebeing effective on deenergization of the magnet to rock the dog to bringan opposite end portion thereof into the path of the lever, the latterend portion being effective to lock the lever against movement until thedog is rocked in the opposite direction by energization of theelectromagnet.

6. A switch comprising a bracket, a contact operating lever movable toeither of two positions of rest pivotally mounted in the bracket, meansfor retaining the lever in one of the positions of rest, comprisin anelongated dog having a curved cam surface on one edge thereof, a pivotdisposed in approximately the mid-section of the dog mounting the dog onthe bracket immediately beyond the end of the lever with the curved camsurface disposed toward the lever to be engaged thereby, anelectromagnet, an armature therefor having a retracting spring, a linkcoupling the armature to the dog whereby the armature is effective onenergization of the electromagnet to rock one end of the dog into thepath of the dog in the opposite direction to move the lever to theopposite position of rest.

7. A switch comprising a bracket, a contact operating lever movable toeither of two positions of rest pivotally mounted in the bracket, meansfor retaining the lever in one of the positions of rest comprising anelongated dog having a curved cam surface on one edge thereof, a pivotdisposed in approximately the mid-section of the dog mounting the dog tothe bracket immediately beyond the end of the lever with the curved camsurface disposed toward the lever to be engaged thereby, anelectromagnet, a spring retracted armature therefor so coupled to thedog as to rock one end portion thereof into the path of the lever onenergization of the magnet to engage and yieldingly hold the leveragainst movement, spring means effective onthe deenergization of themagnet and the resulting rocking of said end of the dog out of the pathof the lever to move the lever to its opposite position of rest, andmeans on said dog effective to positively lock the lever in the latterposition so long as the electromagnet I is deenergized.

JACK 0. WILSON.

REFERENCES CITED The following references are of record in the file ofthis patent:

" UNITED STATES PATENTS Number Name Date 786,017 Dutton Mar. 28, 1905937,122 Waterman Oct. 19, 1907 1,050,791 Beach Jan. 21, 1913 1,288,738Suren Dec. 24, 1918 1,313,019 Schmitz Aug. 12, 1919 2,049,397 MerkelJuly 28, 1936 2,072,510 Moloney Mar. 2, 1937 2,079,577 Parsons May 4,1937 FOREIGN PATENTS Number Country Date 419,727 France Jan. 13, 1911

